In many small and medium-sized companies as well as private computers, back-up procedures include backing up data to a removable medium, such as a backup tape, CD-ROM, storage means on the Internet, Local Area Network, or the like. Many computer programs for backing up data includes a verification test, normally based on bit-by-bit test to verify the data on the removable medium directly against the primary storage means after conclusion of the backup procedure. It is however not until the backup medium is to be used for restoring data, that it is confirmed that a functional backup has been achieved the actual day.
Furthermore, in most cases when a server fails a new server has to be provided and configured before backup data may be restored to establish the full server function. Prior art has presented several solutions to these problems. U.S. Pat. No. 5,907,672 (Matze et al) describes a system for backing up data at a very high speed by saving a logical image copy of the volume to a backup medium. The logical Image may then be restored in its entirety to a disk volume with a different physical geometry in a disaster recovery mode, however the backup procedure does not include any functional test of the data located on the backup medium.
Data may also be protected against failure due to faulty storage device by “disk mirroring”, in which data are stored redundantly on two or more disks. In U.S. Pat. No. 6,044,444 (Ofek) two data systems are interconnected by a data link for remote mirroring of data. That provides a copy of a server, whereby the copy may be stored at a location remote from the server, and the data on the copy are not at risk of being damaged in case any physical damage should occur to the server. However, the data on the copy is erased continuously by reading/mirroring new data to the copy. Thereby it is not possible to obtain and store backup data from previous days. In U.S. Pat. No. 5,978,565 (Ohran et al) a backup computer system runs a special mass storage access program that communicates with a mass storage emulator program on a network file server, making disks on the backup computer system appear like they were disks on the file server computer, whereby normal disk mirroring option of the file server operating system can be activated so that a copy of all data written to the mass storage device directly connected to the file server will also be written to the mass storage device on the backup computer. Then the backup computer system may function as a stand-in computer in case of server failure. However, no backup on a removable medium is provided.
U.S. Pat. No. 5,608,865 (Midgely et al) describes a stand-in system with backup media, wherein a stand-in computer creates an image of a file system on a server. The files on the stand-in computer are then copied to a backup medium, so that only the most recently created files are directly available on the stand-in computer, and the rest of the files may be retrieved from the backup medium. There is no test of the data on the backup medium, unless they are requested to be retrieved by the stand-in computer. Accordingly, no functional test of the data on the backup medium is conducted.
In EP 910019 ((INCM) Int. Computers Ltd.) a backup server is remotely connected to client computers via a public network and automatically performs regular backups of data from the client computers. The backed up data is stored in an automated tape library, and is periodically cloned to provide copies for off-site storage. However, no functional test of the data on the backup media is provided.
In U.S. Pat. No. 6,182,212 (IBM) a method for automating migration of system settings from an existing computer to a replacement computer system in response to a user input is described for use with user upgrades to a new hardware platform. However, there is no disclosure of the automatic migration of settings in connection with backup procedures.
In GB 2270779 a method for transfer of data and programs from a live computer database system to a back-up computer database system and for maintaining the back-up computer database system in readiness for emergency use is disclosed. The method implies conversion of programs and data on the live computer database system and transferring program and data to the back-up computer database system. Brief integrity checks are made on data in the back-up and live computer database system and balancing tests involving statistical analysis of the data tables in both computer database systems and verifying that data stored in both systems is the same. Balancing tests involve generation of statistics about a data table. The statistics include the number of rows in the table and may also include other values for example, the total value of a particular column.
However, GB 2270779 does not disclose any functional verification of the data on the back-up computer database system. The only verification of the data are statistical verification, such as number of rows and columns. Statistical verification only verifies that the same amount of datatables are transferred to the backup system, but is totally silent about the functionality of the data transferred. The system used comprises two computers, wherein the only disclosed communication between the two computers are through a back-up tape, thus verification cannot be performed on-line in GB 2270779.